Carburetor venturi construction



Get. 1., 1950 F. A. KOMMER 2,525,036

CARBURETOR VENTURI CONSTRUCTION Filed 001;. 14, 1947 9/ 4a 2a 6 y 2 7 INVENTOR FRED A. KOMMER I AT|ORN E Y enema a. 10, 1950 2,525,036

UNITED STA ES PATENT OFFICE CABBUBETOR CbNSTRUCTiON Carter Carburetor Corporation, St. Louis, Mo., a corporation of Delaware Application October 14, 19 47, serial No. 776,757

12 Claims. 1

This invention relates to carburetors for internal combustion engines, as automotive engines and the like, and has particular reference to the provision of a carburetor fuel nozzle and Venturi by way of the primary Venturi, and the relation- A further object is to provide improvements section ofimproved construction and to a novel in the structure of, and method of making. a method of forming the nozzle and Venturi assemnozzle Venturi section which will permit of subbly for carburetors of the so-called "low angl tantial savings in the cost of manufacture. e" t I Other objects and advantages of the invention Carburetors of the type. indicated ofier certain will appear from the following description thereof definite advantages in meeting given carburetor and} from the accompanying drawin in which; performance characteristics, as is well under- Fig. 1 is a sectional view vertically through a stood. However, because of the low angle nozzle" downdraft carburetor embodying the present imarrangement wherein the fuel nozzle enters the ,ptovements.

primary Venturi passage atan angle nearly nor- Fig. 2 is a top plan view of the body section of mal to the axis of the Venturi passage, or as oththe carburetor further illustrating the invention. erwise stated, at an angle such that the longitudi- Fig, 3 is an enlarged view, in perspective, of a mi axis of the nozzle in projection across the member providing a wall element which, in as- Venturi passage intersects the Venturi wall oppo-y semblyof the member to the Venturi section in site the nozzle, certain difiiculties have been enaccordance with the present invention, serves'to countered heretofore in the construction of Venc mplete the primary Venturi wall. turi sections having the indicated character of Fig. 4 is a perspective view illustrating a modinozzle and primary Venturi assembly. The gen fled form of the member shown in Fig. 3. oral or prevailing practice is to provide for in Fig. 5 is a fragmentary view of the Venturi secserting the nozzle by drilling from the exterior tion shown in perspectvie and illustrating in a of the section at one side, and in instances where '5 position separated from the primary Venturi wall, the carburetor body includes the float bowl asa a modified form of wall element adapted for aspart thereof, this frequently necessitates drilling mbly o h P m V i W ll to mpl te through a wall or walls of the bowl. Thereafter, thesame. the drill openings in the fioat bowl walls are Although not limitedtoadowndraft carburetor. closed, as by seal plugs. Among the difiiculties the invention is here illustrated in application and disadvantages attending such manner of atto a carburetor of this type. As appears in Fig. 1, taining a low angle nozzle and Venturi arrangethe carburetor shown comprises in superposed ment, may be noted the following: 7 1 assembly, an air horn Iii having a choke valve H Accurate nozzle passage drilling and seating i a V i r dy ion I! and a and positional calibration of the nozzle element th ot l dy I including a hro tle valve ii are diflicult of attainment; the plugged drill opentherein. The throttle body provides a mounting ings in the float bowl walls ofi'er zones of possible flange It by which the carburetor is attached to leakage; and the manufacturing costs are adthe intake manifold of an internal combustion versely enhanced, in consequence of nozzle pasen in not h wn n h Pr e p the sage drilling from the exterior and through the Venturi casing section I 2 provides at one side a float bowl walls, and the necessary provision of liquid fuel chamber l8 the upper open end it of seal plugs in the drill openings. which is closed by a cover 20 formed as a lateral Accordingly, it is an object of the present inextension of the air horn l0. Chamber II is vention to provide a carburetor Venturi section vented to atmosphere as by a tube 22 preferably affording a low angle nozzle-Venturi assembly 5 extending to the air inlet end of the air horn. wherein the section is characterized by an im-. Within the fuel chamber is the usual float valve proved construction such as to avoid the difiiculmechanism indicated generally by the numeral 23. ties and disadvantages encountered heretofore in The Venturisection I2 provides therein a Venconnection with known and prevailing construc-' turi stack affording a primary Venturi passage tions. 24, an intermediate Venturi passage 28 and 3 Another and equally important object of the main Venturi passage 21, the last being defined invention is to provide a novel and effective methby the interior wall 28 of the body section. Venod of forming ormaking' a Venturi section havturi passage 26 is defined by a Venturi-forming ing a nozzle-Venturi assembly of the character circular wall 30, while the primary Venturi pasindicated, whereby the nozzle may be inserted to sage 24 is defined in part by a circular wall Ii hereinafter to be more fully described, the walls 88 and ti being supported preferably by diametrically opposite webs 82 and 84 integral withthe Venturi walls and the casing section. The main fuel system is provided in the Venturi section and includes a vertical passage 88 which receives fuel from the fioat chamber II as through a suitable metering orifice (not shown), and conducts fuel to an inclined passage 88 leading to the primary venturi, the passage 38 extending through the web 34 which is of sufiicient thickness to accommodate the passage. In passage 88 is a suitable fuel nozzle element 88 which projects therefrom into the primary Venturi passage 24, the nozzle terminating in a discharge tip 38 near the axis of the Venturi passage. Air is bled to the main fuel system as from the fioat chamber .vent through a passage 48 and a tube 42 having ports 48 opening to the fuel passage 88. Tube 42a constitutes part of the idling system discharging through porting (not shown) adjacent and posterior to the throttle when closed.

As appears from the view of Fig. 1, the nozzle element 88 enters the primary Venturi passage 24 at a relatively low or sharp angle with respect to a horizontal plane through the venturi. The inclination of passage 88 is such that its longitudinal axis intersects the wall of the primary Venturi tube so that the nozzle cannot be inserted from inside the tube without mutilation thereof. Wall element 44 is'here provided as a separate part for a purpose presently to be described. and is assembled to the wall 3| in a manner which will appear hereinafter.

Turning now to the present improved method of providing the fuel nozzle and primary Venturi assembly, as shown by Fig. 1. body section I! is formed, as by casting, to afford the Venturi stack therein wherein the primary Venturi wall ii is incomplete in its circular extent inwardly of the inlet throat end 48 thereof, to provide a side opening, such as that shown at 48 in Fig. 5, defined by side margins 41 and bottom margin 48 (Figs. 1 and 2). Moreover, in casting the section, web 32 is provided such that it terminates in an upper horizontal end margin 88 a predetermined distance below the upper end 8| of the section while the side opening in wall If is disposed in centered relation to and extends above the end 50 of the web. The side opening thus is located diametrically opposite passage 38 drilled into the casting through which the nozzle 38 is to extend. The section, as cast, includes also a lateral extension 54 providing therein a pocket or recess 88 above and adjoining the outer end of the web margin 50, the recess serving a purpose to appear.

In accordance with the present method, passage 88 is drilled from the inner end by extension of a drill over the web margin 88 and through the Venturi wall side opening 48. Nozzle element 88 is then applied through Venturi wall opening 48 and firmly seated in passage 38. The nozzle is retained in place preferably by pressfit thereofin the passage. In so mounting the nozzle, the'Venturi passage 24 and wall side opening 48 afiord full access to the nozzle, permitting of its adjustment in relation to the primary Venturi passage. Once the nozzle is assembled and adjusted, the wall side opening 48 is closed by the wall element 44 heretofore mentioned, which is shaped in accordance with the Venturi-com touring of the wall Si in the region of the wall opening 48, whereby the wall 3| is thus completed to afford a full primary Venturi passage.

with reference to Figs. 1, 2, and 3. wall element 44 is provided as an integral part of a pre-formed member comprising a relatively thin stem or fln 88 having the wall element 44 at one end. and a block-like part 8| at its opposite end. The block 8| is provided with a recess or channel 82 extending transversely in its upper surface 84, while the wall 44 is undercut to provide a shouldered bottom margin 88. In assembly to the Venturi section, the preformed member is arranged on the margin 88 of web 32 with the block 8i in the casing recess 88 and the wall 44 in the Venturi wall opening 48. The lower margin 48 of the latter opening is shouldered at 88 to receive the shouldered margin 88 of wall element 44 in lap-fit therewith (Fig. l), and the dimensions of the wall element 44 with respect to the opening 48 are predetermined such as to afford substantially a press-fit of the wall element in the opening. Once in place. the preformed member is securely locked in assembly to the Venturi casing section as by staking or peening marginal portions 88 (Fig. 2) of the casing at the recess 88, into the block channel 82 at the opposite ends of the latter. It is to be noted that the fin 88 is of a thickness corresponding to that of the web 82. so that the fin in effect is an upward extension of the web, completing the latter to the top end of the Venturi casing section.

Fig. 4 illustrates a modification of the preformed member shown. in Fig. 3. the difference residing in the partial undercutting of the side margins 18 of the wall element 44, to afford shoulders ll, these being in addition to the bottom marginal shoulder 88. In order to receive the modified wall element, the side margins 41 ofthe Venturi wall opening 48 will have to be modified in the casting of the Venturi casing section. such as toafl'ord complemental shoulders (not shown) for lap-fit with the shoulders ll.

Fig. 5 discloses a modification in the manner of completing the primary Venturi wall. According to this view, the Venturi casing section is formed or cast as in the instance of the section of Fig. 1, to include a primary Venturi wall 12 which is here incomplete not only in one side thereof, affording the side opening 48, but at its upper end such that the wall terminates at 14 short of the Venturi entrance throatportion such as that indicated at 48 in Fig. 1. In this embodiment. the wall opening 48 is defined by side margins 18 and bottom margin 18 shouldered at 11, while the end terminal margin 14 is internally shouldered at I8.

Following drilling of the nozzle passage and assembly insertion of the nozzle element, the Venturi wall I! is completed by a pro-formed member 88 having a wall element 8|, the lower margin 82 of which is shouldered, and an annular wall part 88 shaped to provide a Venturi inlet throat 84. The annular wall part is undercut to afi'ord a shouldered margin 88 extending from one side margin 88 of wall element 8| to the opposite side margin 81 of the latter. The member 88 is dimensioned for a press-fit with the Venturi wall 12, such that in assembly to the latter, the shoulders 82 and 88 have a firm ,lap-fit with the respective shoulders TI and 18 of wall 12, while the side margins 88 and 81 are in pressed-engagement with the side margins 18 low angle nozzle type, the nozzle passage may be drilled with greater facility and greater accuracy as to the angular disposition thereof, while the nozzle element may be more easily inserted and accurately adjusted in place. Moreover, the present method avoids the disadvantages and difficulties including those hereinbefore noted, attending the older practice of drilling the nozzle passage from the outside of the body section, as through the outer wall 90 openings in these walls.

Having now illustrated and described the invention, all modifications thereof in addition to the several embodiments herein disclosed, which come within the spirit and intended scope of the appended claims are contemplated.

I claim:

1. The method of making a carburetor Venturi section having a Venturi passage and a fuel nozzle therein, wherein the longitudinal axis of the nozzle in extension across the Venturi passage intersects the wall of the venturl, which comprises forming the Venturi section to have a Venturi-forming wall incomplete in its extent such as to leave an opening in one side thereof, forming a nozzle-receiving passage in the section by drilling through the Venturi wall with the drill extended through the side opening in the wall, thence arranging a nozzle element through the Venturi wall side opening and displacing the element into position in the nozzle-receiving passage of the section, and thereafter mounting a preformed wall element to the Venturi wall to close the side opening therein and complete the Venturi wall.

2. The method of making a carburetor Venturi section embodying a low angle fuel nozzle, which comprises forming the Venturi section to have a Venturi wall incomplete in its extent such as to leave arr-opening in one side thereof, forming a nozzle passage in the section extending through the Venturi wall at a point opposite the wall side opening by drilling through the wall with the drill extended through the wall side opening, inserting a nozzle element in the drilled passage, and thereafter press-fitting a preformed wall section to the incomplete Venturi wall to close the side opening thereof and complete the wall.

3. The method of making a carburetor Venturi section embodying a low angle fuel nozzle, which comprises forming the Venturi section to have a Venturi stack including a primary Venturiforming wall incomplete in its extent such as to leave an opening in one side thereof, thence forming a nozzle passage in the section by drilling through the primary Venturi wall at a point opposite the wall side opening with the drill nomle element through said Venturi side opening and into the drilled passage, applying a preformed member having a wall element to the Venturi section with the wall element thereof in theside opening of the Venturi wall, to complete the latter, and thereafter anchoring the preformed member to the Venturi'section.

5. The method of making a carburetor Venturi section embodying a low angle fuel nozzle, which comprises forming the Venturi section to have a primary Venturi wall incomplete in its extent, such as to leave an opening in one side thereof, with the wall margin defining the side opening having at least a portion thereof shouldered, thence forming a nozzle passage in the section by drilling through the Venturi wall at a point opposite the side opening with the drill extended in and through such side opening, inserting a fuel nozzle element in the drilled passage, and thereafter inserting a pre-formed wall section in the side opening of the Venturi wall in lapfltted relation to the shouldered portion of the wall margin defining the opening, to close the opening and complete the primary Venturi wall.

6- The method of making a carburetor Venturi section embodying a low angle fuel nozzle, which comprises forming the Venturi section to have a primary Venturi wall incomplete in its extent such as to characterize the same by an opening in one side thereof, and by the absence of a wall portion defining the Venturi inlet throat, thence forming a nozzle passage in the Venturi section by drilling through the primary Venturi wall at a point opposite the side opening with, the drill extended in and through such side opening, inserting a nozzle element in the drilled passage, and thereafter mounting a preformed wall section including a portion defining a Venturi inlet throat to ,the incomplete Venturi wall, thereby closing the side opening and providing the Venturi wall with an inlet throat.'

I. The method of making a carburetor Venturi section embodying a low angle fuel nozzle, which comprises forming the Venturi section to have a Venturi-forming wall incomplete in its extent such as to leave an opening in one side thereof,

- thence forming a nozzle passage in the section extended in and through such side opening,

to leave an opening in one side thereof, thence forming a nozzle passage in the section by drilling through the Venturi wall at a point opposite the side opening thereof, with the drill extended in and through such side opening, inserting a by drilling through the Venturi wall at a point opposite the wall side opening, with the drill extended in and through such side opening, arranging a nozzle element in and through the Venturi wall side opening and thence displacing the nozzle into position in the drilled nozzle passage, and thereafter mounting a preformed wall element to the Venturi wall to close the side opening and complete the Venturi wall.

8. In a carburetor, a Venturi section providing therein a Venturi tube having a portion" thereof which is incomplete in its circular extent, a wall element arranged onsaid tube in a position to complete said tube portion such as to' afford a full circular extent thereof, and a fuel nozzle extending through the Venturi tube and directed such that its longitudinal axis in extension forwardly of the nozzle, intersects said wall element.

9. In a carburetor, a Venturi section providing therein a Venturi tube having a portion thereof which is incomplete in its circular extent,

"a wall element on said tube in a position to complete said tube portion such as to afford a full circular extent thereof, said wall element being marginally lap-fitted in assembly to the tube, and a fuel nozzle extending through said tube and directed such that its longitudinal axis asaaosein extension forwardly of the nozzle, intersects said wall element.

10. In a carburetor, a Venturi section providing therein a Venturi tube having a portion thereof which is incomplete in its circular extent, 5

a wail element on said tube in a position to complete said tube portion such as to aflord a full circular extent thereof, a fuel nozzle extendinl; through said tube and directed such that its longitudinal axis in extension forwardly of the nozzle, intersects said wall element, said well element having a press-fit with said Venturi tube, and means securing the wall element to the Venturi section.

11. In a carburetor, a Venturi section providing therein a generally tubular member having a wall section which is incomplete in its circular extent, a sector-like wall element in lap-fitted assembly with said wall section and completing the same such as to afford a full circular extent 20 thereof, said member being fixed to the Venturi 'section and defining with said wall element, a

Venturi passage, and a fuel nozzleextending through the member and terminating in the Venturi passage, said nozzle being directedsuch that its longitudinal axis in extension forwardly of the nozzle, intersects said wall element.

12. In a carburetor, a Venturi section provid- 8 ing therein a generally tubular member having a wall section at one end which is incomplete in its circular extent,'a sector-like wall element including an annulus thereon, in lap-fitted assembly with said wall section and completing the latter such as to ailord a full circular extent thereof, said annulus being concentric with the end of said wall section, said member defining with said wall element and its annulus, a Venturi passage, and a fuel nozzle extending through the member into the Venturi passage, said nozzle being directed such that its longitudinal axis in extension forwardly of the nozzle, intersects said wail element insert. A

m A- KO names crran 'l'fhe following references are of record in the file of this patent:

UNITED s'm'rns PATENTS Number Name Date 1,925,788 Gardner Oct. 6, 1931 1,931,259 Kirby Oct. 1'7, 1933 25 2,312,818 Heitler Mar. 2, 1943 2,332,440 meson Oct. 19, 1943 2,399,019 Winhler Nov. 27, 1945 

